The present invention relates to articulated vehicles and, more particularly, to a stabilization system for resisting the roll-over of an articulated vehicle.
Articulated vehicles, such as articulated dump trucks (ADT's) are well-known in the art. For example, ADT's typically include a cab portion having a first frame supporting an operator cab, and a trailer portion having a second frame supporting a bin. The bin is configured to contain a load and is typically coupled to an actuator for angular movement relative to the second frame. The first frame and the second frame may be operably coupled through a universal joint including a pivot frame coupling for providing articulated movement of the first frame relative to the second frame about a vertical axis, and an oscillation frame coupling for providing oscillatory movement of the second frame relative to the first frame about a longitudinal axis. A first wheel assembly supports the first frame, and a second wheel assembly supports the second frame. The second wheel assembly includes a rotatably supported front wheel and a rotatably supported rear wheel. The front wheel and the rear wheel are coupled to a tandem or walking beam which, in turn, is pivotally coupled to the second frame by a tandem coupling. As such, the front wheel and the rear wheel are supported for pivoting movement about the tandem coupling to facilitate continuous wheel engagement over rough terrain.
ADT's may suffer from stability issues when not operated or loaded correctly. For example, instability may arise from the ADT being poorly loaded (too much weight too far forward on the bin), being near the end of the articulation range, and may be aggravated by operating in such a condition at relatively high speeds. Such stability issues may result in a “bin dump” condition where the center of gravity of the trailer portion moves outwardly over a line of action extending from the pivot frame coupling to the tandem coupling. In this condition, the trailer portion rolls over while the cab portion remains upright. While such a roll-over typically does not cause permanent equipment damage or operator injury, it causes the ADT and a related excavator to be out of commission until the trailer portion is uprighted.
According to an illustrative embodiment of the present invention, a vehicle includes a chassis having a cab portion, a trailer portion, and a coupling assembly being positioned between the cab portion and the trailer portion. The trailer portion is configured to support a load, and defines a longitudinal axis and a center of gravity. The coupling assembly includes a pivot coupling configured to provide pivoting movement between the cab portion and the trailer portion about a vertical axis. A wheel assembly is coupled to the trailer portion. A line of action is associated with the trailer portion. A stabilization system is operably coupled to the chassis, and is configured to move the line of action outwardly in response to changes in a vehicle condition.
According to a further illustrative embodiment of the present invention, a vehicle includes a first frame, a first wheel assembly operably coupled to the first frame, a second frame defining a longitudinal axis, and a second wheel assembly operably coupled to the second frame. The second wheel assembly includes a tandem pivotally coupled to the second frame at a pivot coupling, a front wheel rotatably supported by the tandem, and a rear wheel rotatably supported by the tandem. A bin is supported by the second frame and is configured to support a load. A frame coupling is positioned between the first frame and the second frame, and is configured to provide pivoting movement between the first frame and the second frame about a vertical axis. A vehicle condition sensor is configured to detect a condition of the vehicle. A controller is in communication with the vehicle condition sensor. A stabilizer is operably coupled to the second frame and the tandem, and is configured to restrict pivoting movement of the tandem in response to the condition sensed by the vehicle condition sensor.
According to yet another illustrative embodiment of the present invention, a method of stabilizing a vehicle includes the steps of providing a vehicle having a first frame and a second frame that are pivotally connected to one another by a pivot frame coupling to steer the vehicle. The first frame has a first wheel assembly and the second frame has a second wheel assembly. The second wheel assembly includes a tandem pivotally coupled to the second frame, a front wheel rotatably supported by the tandem and a rear wheel rotatably supported by the tandem. A stabilizer is operably coupled to the tandem. The method further includes the step of pivoting the first frame relative to the second frame about the pivot coupling. The method also includes the steps of sensing a vehicle condition and controlling the stabilizer in response to the sensed vehicle condition.
Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrative embodiment exemplifying the best mode of carrying out the invention as presently perceived.